EP3627467A1 - Method and device for detecting the state of a front bonnet of a motor vehicle by comparing fields of view - Google Patents

Abstract

A detection method is implemented in a motor vehicle (V) comprising a front cover (CV) having a normal state in which it is completely closed in order to circulate and a camera (CO) coupled to an upper part of the windshield (PB) and acquiring images forward. This process includes:
a first step in which the field of vision of the camera (CO) is determined in each acquired image, then each field of vision determined is compared to a reference field of vision, determined in a reference image acquired when the front cover (CV) was in its normal state, and
- a second step in which, if a difference in field of vision is determined, it is considered that the front cover (CV) is not in its normal state, and an alarm is generated in order to warn the driver.

Description

The invention relates to motor vehicles comprising a front cover, and more precisely the detection of the state in which the front cover of such vehicles is located.

As those skilled in the art know, certain vehicles (motor vehicles) include a detection device responsible for detecting the opening of their front hood. This detection device generally comprises a contactor which is coupled to the locking / unlocking mechanism of the front cover, as described in particular in the patent document. DE 10148639 . When this contactor detects the opening of the front hood, it generates an alarm intended to inform the driver of the vehicle and possibly to trigger the implementation of a safety strategy, such as for example the shutdown of the motor-fan unit (or GMV ).

This type of detection device requires a dedicated contactor and a specific installation generally requiring an adaptation of the locking / unlocking mechanism. In addition, it induces an increase in the mass of the vehicle, is subject to mechanical wear, can be the subject of malfunctions, and generally requires a specific connection for the transmission of its alarm signal (or message). and its power supply. In addition, this type of detection device does not always make it possible to detect, and therefore to report, damage to a front cover following a shock.

The invention therefore aims in particular to improve the situation.

It proposes in particular for this purpose a detection method intended to be implemented in a motor vehicle type and comprising a front cover having a normal state in which it is completely closed in order to circulate and a camera coupled to an upper part of a windshield and acquiring images towards the front of the vehicle.

• une première étape dans laquelle on détermine dans chaque image acquise un champ de vision de la caméra, puis on compare chaque champ de vision déterminé à un champ de vision de référence, déterminé dans une image de référence acquise lorsque le capot avant était dans son état normal, et
• une seconde étape dans laquelle, en cas de détermination d'au moins une différence de champ de vision, on considère que le capot avant n'est pas dans son état normal, et on génère une alarme afin d'avertir un conducteur du véhicule.

This detection method is characterized by the fact that it comprises:

• a first step in which a field of vision of the camera is determined in each acquired image, then each field of vision determined is compared to a reference field of vision, determined in a reference image acquired when the front cover was in its state normal, and
• a second step in which, if at least one difference in field of vision is determined, it is considered that the front cover is not in its normal state, and an alarm is generated in order to warn a driver of the vehicle.

Thus, we can now monitor the state in which the front cover of a vehicle is placed using images acquired by an on-board camera, possibly for at least one other function, and therefore without having to couple a contactor to the mechanism. locking / unlocking the front cover.

• dans sa première étape on peut déterminer dans chaque image acquise le champ de vision de la caméra en déterminant chaque zone permettant une observation au-delà d'une extrémité avant du capot avant ;
• dans sa seconde étape on peut comparer la différence de champ de vision déterminée à au moins deux différences de champ de vision prédéfinies, correspondant respectivement à des problèmes différents au niveau du capot avant, afin de déterminer parmi ces problèmes celui qui correspond à la différence de champ de vision prédéfinie qui est similaire à la différence de champ de vision déterminée, et on peut générer une alarme qui est représentative de ce problème déterminé ;
  • 
    dans sa seconde étape les problèmes peuvent être choisis parmi un déverrouillage partiel du capot avant correspondant à une première réduction par le bas d'un secteur angulaire d'observation suivant une direction verticale, une déformation du capot avant correspondant à une deuxième réduction par le bas du secteur angulaire d'observation suivant cette direction verticale, supérieure à cette première réduction, et une ouverture au moins partielle du capot avant correspondant au moins à une troisième réduction dans une partie centrale du secteur angulaire d'observation suivant cette direction verticale, supérieure à cette deuxième réduction ;
• dans sa seconde étape on peut générer une alarme qui requiert une action sur le déplacement du véhicule ;
• dans sa seconde étape on peut générer l'alarme en cas de détermination d'une même différence de champ de vision dans au moins deux images acquises successivement.

The detection method according to the invention may include other characteristics which can be taken separately or in combination, and in particular:

• in its first step, the field of vision of the camera can be determined in each acquired image by determining each zone allowing observation beyond a front end of the front cover;
• in its second step, the determined difference in field of vision can be compared with at least two predefined differences in field of vision, corresponding respectively to different problems at the front cover, in order to determine which of these problems corresponds to the difference in predefined field of vision which is similar to the difference of determined field of vision, and an alarm can be generated which is representative of this determined problem;
  • 
    in its second stage, the problems can be chosen from a partial unlocking of the front cover corresponding to a first reduction from the bottom of an angular sector of observation in a vertical direction, a deformation of the front cover corresponding to a second reduction from the bottom of the angular sector of observation in this vertical direction, greater than this first reduction, and an at least partial opening of the front cover corresponding to at least one third reduction in a central part of the angular observation sector in this vertical direction, greater than this second reduction;
• in its second step, an alarm can be generated which requires action on the movement of the vehicle;
• in its second step, the alarm can be generated if the same difference in field of vision is determined in at least two images acquired successively.

The invention also provides a computer program product comprising a set of instructions which, when executed by processing means, is capable of implementing the detection method described above for detecting a state in which is placed a front cover of a motor vehicle.

The invention also provides a detection device intended to equip a motor vehicle type and comprising a front cover having a normal state in which it is completely closed in order to circulate and a camera coupled to an upper part of a windshield and acquiring images towards the front of the vehicle.

• déterminant dans chaque image acquise un champ de vision de la caméra, puis
• comparant chaque champ de vision déterminé à un champ de vision de référence, déterminé dans une image de référence acquise lorsque le capot avant était dans son état normal, et
• en cas de détermination d'au moins une différence de champ de vision, considérant que le capot avant n'est pas dans son état normal, et déclenchant la génération d'une alarme afin d'avertir un conducteur du véhicule.

This detection device is characterized by the fact that it comprises at least one computer:

• determining in each acquired image a field of vision of the camera, then
• comparing each determined field of vision with a reference field of vision, determined in a reference image acquired when the front cover was in its normal state, and
• in the event of determination of at least one difference in field of vision, considering that the front cover is not in its normal state, and triggering the generation of an alarm in order to warn a driver of the vehicle.

The invention also provides a motor vehicle comprising a front cover having a normal state in which it is completely closed in order to circulate, a camera coupled to an upper part of a windshield and acquiring images towards the front of the vehicle, and a detection device of the type presented above.

• la figure 1 illustre schématiquement et fonctionnellement, dans une vue en coupe dans un plan longitudinal, une partie avant d'un véhicule équipé d'une caméra, d'un exemple de réalisation d'un dispositif de détection selon l'invention, et d'un capot avant placé dans un état normal (totalement fermé),
• la figure 2 illustre schématiquement et fonctionnellement, dans une vue en coupe dans un plan longitudinal, le véhicule de la figure 1 avec son capot avant placé dans un premier état anormal (partiellement ouvert),
• la figure 3 illustre schématiquement et fonctionnellement, dans une vue en coupe dans un plan longitudinal, le véhicule de la figure 1 avec son capot avant placé dans un second état anormal (totalement ouvert), et
• la figure 4 illustre schématiquement un exemple d'algorithme mettant en oeuvre un procédé de détection selon l'invention.

Other characteristics and advantages of the invention will appear on examining the detailed description below, and the appended drawings, in which:

• the figure 1 illustrates schematically and functionally, in a sectional view in a longitudinal plane, a front part of a vehicle equipped with a camera, of an exemplary embodiment of a detection device according to the invention, and of a hood before placed in a normal state (fully closed),
• the figure 2 illustrates schematically and functionally, in a sectional view in a longitudinal plane, the vehicle of the figure 1 with its front cover placed in a first abnormal state (partially open),
• the figure 3 illustrates schematically and functionally, in a sectional view in a longitudinal plane, the vehicle of the figure 1 with its front cover placed in a second abnormal state (fully open), and
• the figure 4 schematically illustrates an example of an algorithm implementing a detection method according to the invention.

The object of the invention is in particular to propose a detection method, and an associated DD detection device, intended to detect the state in which the front cover CV of a vehicle V of the automobile type is placed.

In what follows, it is considered, by way of nonlimiting example, that the motor vehicle V is a car. However, the invention is not limited to this type of motor vehicle. It in fact relates to any type of motor vehicle comprising a front cover rotatably mounted in a front part, for example in the vicinity of the lower edge of the windshield.

We have schematically represented on the Figures 1 to 3 a vehicle (motor vehicle) V equipped with a camera CO, a detection device DD according to the invention, and a central handset CC comprising a display screen responsible for displaying images.

Note that in the example illustrated without limitation on the figure 1 , vehicle V comprises only a single display screen forming part of the central handset CC permanently installed in or on the dashboard PDB. However, the vehicle V may include several display screens installed permanently or temporarily. Thus, it can include a display screen in its dashboard (fixed) and / or part of its windshield PB can serve as a display screen for a display device of the so-called "head-up" type and / or it can temporarily transport a smart mobile phone (or "smartphone") or an electronic tablet comprising a screen. display, for example.

As mentioned above, the invention proposes in particular a detection method intended to allow the detection of the state in which the front cover CV of the vehicle V is placed. This method comprises first 10-30 and second 40-80 steps which can be implemented at least partially by a DD detection device according to the invention, on board the vehicle V and comprising, as illustrated in the figure 1 , at least one CA computer. For example, this CA computer can include at least one digital signal processor (or DSP ("Digital Signal Processor")), possibly associated with at least one memory.

Note that in the example illustrated without limitation on the figure 1 , the DD detection device is equipment which is permanently installed in vehicle V. But at least the computer CA of the DD detection device could be installed in mobile communication equipment, temporarily on board in vehicle V (as for example example a smart phone or an electronic tablet), and able to communicate by wave and / or by wire with at least one electronic device of vehicle V.

The invention requires that vehicle V be equipped with at least one CO camera coupled to an upper part of its windshield PB and responsible for acquiring digital images towards the front, and therefore above, and in front , its front cover CV, as well as possibly on a front part of its two lateral sides. This CO camera can possibly be part of the DD detection device, but this is not compulsory. Indeed, the camera CO can possibly acquire images useful for at least one other function than that of detection described below.

Note that in the example illustrated without limitation on the figure 1 , the CO camera is installed in the central interior mirror RI which is fixedly secured to the upper part of the windshield PB. But this CO camera could be fixedly secured to the upper part of the PB windscreen or integrated into an external part of the roof or pavilion.

As illustrated in the figure 1 , this camera CO has a reference field of view cv _ref which is maximum when the front cover CV is placed in a so-called normal state because it is kept fully closed by a locking / unlocking mechanism (not shown). It will be noted that in what follows it is considered that the front cover CV is placed in a first state known as abnormal, illustrated on the figure 2 , when it is partially open while being partially retained by a notch of the locking / unlocking mechanism, and in a second state also said to be abnormal, illustrated on the figure 3 , when it is at least partially open without being retained by the locking / unlocking mechanism.

The first abnormal state results from a partial unlocking of the front cover CV, and corresponds to a first reduction from the bottom of the angular sector of observation of the camera CO in the vertical direction. In other words, when the front cover CV is placed in its first abnormal state, the field of vision of the camera CO, noted cv ₁ on the figure 2 , is slightly reduced (below) compared to its reference field of vision cv _ref .

The second abnormal state results from a total unlocking of the front cover CV, and corresponds to another reduction in at least a central part of the angular sector of observation of the camera CO in the vertical direction. In other words, when the CV front cover is placed in its second abnormal state (see figure 3 ), the field of vision of the camera CO is reduced, or even zero, compared to its reference field of vision cv _ref . In the example illustrated without limitation on the figure 3 , the front cover CV is placed in a second abnormal state in which it is completely open and induces a zero field of vision of the CO camera (the latter is therefore not only reduced in its central part, but also in its lower parts (bottom ) and higher (top)).

In the first step 10-30 of the detection method, according to the invention, one (the computer CA) determines in each image acquired by the camera CO the field of vision of the latter (CO). Then, we (the computer CA) compare each determined field of vision to the reference field of vision cv _ref , which was previously determined in a reference image acquired when the front cover CV was in its normal state (illustrated on the figure 1 ).

It will be understood that after each acquisition of an image by the camera CO, the computer CA determines the current field of vision of the camera CO and then compares this current field of vision to cv _ref .

For example, in the first step 10-30 we (the CA calculator) can determine in each acquired image the field of vision in progress of the CO camera by determining each zone allowing observation beyond the front end of the front cover CV (and therefore in front of vehicle V). It is in fact considered that the current field of vision of the camera CO is what allows it to observe the environment at least in front of the front cover CV. In the example of the figure 3 , this current field of vision is zero because the front cover CV prevents any observation of the environment in front of the vehicle V by the camera CO. But it could be envisaged that the rounded shape of the lower (or rear) edge of the front cover CV, located near the windshield PB, allows observation of a very small part of the environment in front of the vehicle V in an included area between this lower edge and the engine compartment, when the CV front cover is fully open. Similarly, it could be envisaged that when the front cover CV is fully open it does not obstruct an upper part of the field of vision of the camera CO. In this case, the camera CO can observe a small part of the environment in front of the vehicle V in an area located above the upper edge (or front) of the front cover CV.

In the second step 40-80 of the detection method on (the computer CA) considers that the front cover CV is not in its normal state in the event of determination of at least one difference in field of vision in the first step 10 -30, and an alarm is generated in order to warn the driver of the vehicle V. It will be understood that it is the CA computer which triggers the generation of this alarm.

The alarm can be in the form of an analog or digital signal or a text, sound or even haptic message. In the case of a text message, the latter can be displayed on at least one display screen permanently or temporarily installed in vehicle V. For example, this display screen can be that of the central handset CC, or the one in the painting on board vehicle V, or part of the windshield PB of vehicle V which is used by a head-up display device, or even that of mobile communication equipment (such as a smart phone or a electronic tablet). This text message can possibly be displayed simultaneously on at least two display screens. In the case of an audible message, the latter can be broadcast by at least one loudspeaker installed permanently or temporarily in vehicle V.

Thanks to the invention it is now possible to monitor the state in which the front cover CV of a vehicle V is placed by using images acquired by an on-board CO camera, possibly for at least one other function (such as for example a assistance in driving the vehicle (possibly of the ADAS ("Advanced Driver Assistance System") type, and therefore without having to couple a switch to the locking / unlocking mechanism of the CV front hood. This offers several advantages. the CO camera already provides images for at least one other function, there is no noticeable increase in mass. In addition, there is no longer any specific implantation and adaptation of the locking mechanism / unlocking to be provided. In addition, there is no longer any risk of mechanical wear. Finally, there is no longer any need for specific connectors.

It will be noted that in the second step 40-80 we (the computer CA) can compare the difference in field of vision determined in the first step 10-30 with at least two predefined differences in field of vision, corresponding respectively to different problems at CV front cover level. This option is intended to determine which of these different problems corresponds to the predefined difference in field of vision which is similar to the difference in field of vision (in progress) determined. In this case, an alarm is generated which is representative of the problem which has been determined. This makes it possible to establish a kind of diagnosis, rather than alerting whatever the cause (and therefore whatever the difference in field of vision determined).

• un déverrouillage partiel du capot avant CV, illustré sur la figure 2 et correspondant à une première réduction par le bas du secteur angulaire d'observation de la caméra CO suivant la direction verticale,
• une déformation du capot avant CV (non illustrée), provoquée par un choc et correspondant à une deuxième réduction par le bas du secteur angulaire d'observation de la caméra CO suivant la direction verticale, supérieure à la première réduction, et
• une ouverture au moins partielle du capot avant CV, illustrée sur la figure 3 et correspondant au moins à une troisième réduction dans une partie centrale du secteur angulaire d'observation de la caméra CO suivant la direction verticale, supérieure à la deuxième réduction.

For example, the aforementioned (and predefined) problems can be chosen from at least:

• partial unlocking of the front cover CV, illustrated on the figure 2 and corresponding to a first reduction from the bottom of the angular sector of observation of the camera CO in the vertical direction,
• a deformation of the front cover CV (not shown), caused by a shock and corresponding to a second reduction from the bottom of the angular sector of observation of the camera CO in the vertical direction, greater than the first reduction, and
• at least partial opening of the front cover CV, illustrated on the figure 3 and corresponding to at least a third reduction in a central part of the angular sector of observation of the camera CO in the vertical direction, greater than the second reduction.

In the presence of such an option, a first alarm can signal a partial unlocking of the front cover CV, a second alarm can signal a deformation of the front cover CV (for example following an impact), which a simple contactor cannot detect of the prior art, and a third alarm may signal an at least partial opening of the front cover CV.

It will be noted that the number of different problems detectable by the computer CA can be equal to two or three, or even more, and that these problems are not limited to the three examples described above.

It will also be noted that in the second step 40-80, an alarm can be generated which requires action on the movement of the vehicle V. In this case, the alarm is also transmitted to another computer which is, for example, in charge of supervision of the motor-fan unit and of the vehicle braking system V. This makes it possible to slow down vehicle V with a view to stopping it so that its driver can completely close the front cover and thus place it in its state normal.

When the alarm is representative of the detected problem, the action on the movement of vehicle V can be variable. Indeed, in the presence of a simple partial unlocking of the front cover CV, the vehicle V can be gradually slowed down until it is immobilized in a secure manner. On the other hand, in the presence of at least partial opening of the front hood CV, vehicle V must be stopped as soon as possible, taking into account the importance of the danger.

It will also be noted that in order to avoid false alarms, in the second step 40-80, it is possible to generate the alarm in the event of determination of a same difference in field of vision in at least two images acquired successively. In other words, the CA computer will only trigger the generation of an alarm if and only if it detects on at least two successively acquired images the same difference in field of vision and therefore the same problem.

We have schematically illustrated on the figure 4 an example of an algorithm implementing the first 10-30 and second 40-80 steps of the detection method described above.

In a first sub-step 10 of the first step, an image is acquired with the camera CO.

In a second sub-step 20 of the first step on (the computer CA) determines in this image acquired by the camera CO the field of vision of the latter (CO).

In a third sub-step 30 of the first step on (the computer CA) compares this determined field of vision to the reference field of vision cv _ref .

In a fourth sub-step 40 of the second step on (the computer CA) determines whether there is actually a difference between the determined field of vision and cv _ref .

In the absence of a difference between the determined field of vision and cv _ref , we (the computer CA) end the detection process in a fifth sub-step 50 of the second step. We then wait for the acquisition of the next image by the CO camera.

On the other hand, in the presence of a difference between the determined field of vision and cv _ref , we (the computer CA) can, in a sixth sub-step 60 of the second step, compare the difference in field of vision determined in the fourth sub-step 40 to at least two predefined field of vision differences, corresponding respectively to different problems at the level of the front cover CV, in order to determine the existing problem. Then, in a seventh sub-step 70 of the second step, an alarm is generated (here representative of the determined problem) in order to warn (at least) the driver of the vehicle V. Then, we (the computer CA) terminates the process detection in an eighth sub-step 80 of the second step. We then wait for the acquisition of the following image by the CO camera.

It will also be noted that the invention also proposes a computer program product comprising a set of instructions which, when executed by processing means of the electronic circuits (or hardware) type, such as for example the computer AC, is suitable for implementing the detection method described above for detecting the state in which the front cover CV of the motor vehicle V.

Note also that on the Figures 1 to 3 the DD detection device is very schematically and functionally illustrated by its computer CA. As mentioned above, this CA computer can be produced by means of at least one processor, for example a digital signal (or DSP (Digital Signal Processor)), possibly associated with a random access memory for storing instructions for implementation by this processor of part of the detection method as described above. Furthermore, the DD detection device can comprise a box comprising integrated (or printed) circuits, connected by wired or non-wired connections. The term integrated circuit (or printed circuit) means any type of device capable of performing at least one electrical or electronic operation. Furthermore, this DD detection device can comprise at least one mass memory in particular for the storage of images and / or data defining the results of its analyzes (of images) and calculations, an input interface for the reception of 'at least the images (which it possibly formats and / or demodulates and / or amplifies in a manner known per se), and an output interface for the transmission of the results of its calculations.

One or more substeps of at least one of the first and second steps of the detection method can be carried out by different components. Thus, the detection method can be implemented by a plurality of processors, random access memory, mass memory, input interface, output interface and / or digital signal processor. In these situations, the DD detection device can be decentralized, within a local network (several processors linked together for example) or a wide area network.

Claims (9)

Detection method for a vehicle (V) of automobile type and comprising a front cover (CV) having a normal state in which it is completely closed in order to circulate and a camera (CO) coupled to an upper part of a windshield (PB) and acquiring images towards the front of said vehicle (V), characterized in that it comprises i) a first step (10-30) in which a field of vision of said camera is determined in each acquired image ( CO), then each determined field of vision is compared with a reference field of vision, determined in a reference image acquired when said front cover (CV) was in said normal state, and ii) a second step (40-80) in which, when determining at least one difference in field of vision, it is considered that said front cover (CV) is not in its normal state, and an alarm is generated in order to warn a driver of said vehicle ( V). Method according to claim 1, characterized in that in said first step (10-30), each field of vision of said camera (CO) is determined in each acquired image by determining each zone allowing observation beyond a front end said front cover (CV). Method according to claim 1 or 2, characterized in that in said second step (40-80), said determined difference in field of vision is compared with at least two predefined differences in field of vision, corresponding respectively to different problems at said level. front cover (CV), in order to determine which of these problems corresponds to the predefined difference in field of vision which is similar to said determined difference in field of vision, and an alarm representative of said determined problem is generated. Method according to claim 3, characterized in that in said second step (40-80) said problems are chosen from a partial unlocking of said front cover (CV) corresponding to a first reduction from below of an angular observation sector following a vertical direction, a deformation of said front cover (CV) corresponding to a second reduction from the bottom of said angular observation sector in said vertical direction, greater than said first reduction, and an at least partial opening of said front cover (CV) corresponding at least to a third reduction in a central part of said angular sector of observation in said vertical direction, greater than said second reduction. Method according to one of claims 1 to 4, characterized in that in said second step (40-80) an alarm is generated requesting an action on a movement of said vehicle (V). Method according to one of claims 1 to 5, characterized in that in said second step (40-80), said alarm is generated in the event of the determination of the same difference in field of vision in at least two images acquired successively. Computer program product comprising a set of instructions which, when executed by processing means, is suitable for implementing the detection method according to one of the preceding claims for detecting a state in which is placed a front cover (CV) of a motor vehicle (V). Detection device (DD) for a vehicle (V) of the automobile type and comprising a front cover (CV) having a normal state in which it is completely closed in order to circulate and a camera (CO) coupled to an upper part of a windshield (PB) and acquiring images towards the front of said vehicle (V), characterized in that it comprises at least one computer (CA) i) determining in each acquired image a field of vision of said camera (CO ), then ii) comparing each determined field of vision with a reference field of vision, determined in a reference image acquired when said front cover (CV) was in said normal state, and iii) in the event of determination of at least a difference in field of vision, considering that said front cover (CV) is not in its normal state, and triggering the generation of an alarm in order to warn a driver of said vehicle (V). Motor vehicle (V) comprising a front cover (CV) having a normal state in which it is completely closed in order to circulate and a camera (CO) coupled to an upper part of a windshield (PB) and acquiring images towards the front of said vehicle (V), characterized in that it further comprises a detection device (DD) according to claim 8.

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